| Age – year | 2600 | +1 | 0.95 [0.94, 0.96] | <0.001 |
| ≤25 | Reference |
| 26 – 30 | 0.91 [0.70, 1.17] | 0.444 |
| 31 – 35 | 0.77 [0.60, 0.99] | 0.041 |
| 36 – 40 | 0.56 [0.42, 0.73] | <0.001 |
| >40 | 0.13 [0.06, 0.27] | <0.001 |
| BMI - kg/m2 | 2573 | +1 | 1.01 [0.98, 1.03] | 0.668 |
| Anti-Müllerian hormone – ng/mL | 2511 | +1 | 1.04 [1.03, 1.06] | <0.001 |
| Antral follicle count – n | 2355 | +1 | 1.03 [1.02, 1.04] | <0.001 |
| Duration of infertility – year | 2425 | +1 | 0.97 [0.96, 0.99] | 0.011 |
| Type of infertility – n (%) | 2600 |
| Primary | Reference |
| Secondary | 0.86 [0.76, 0.97] | 0.016 |
| IVF indication – n (%) | 2600 |
| Male | Reference |
| Tubal | 0.82 [0.70, 0.98] | 0.024 |
| Diminished ovarian reserve | 0.45 [0.34, 0.58] | <0.001 |
| Unexplained | 0.84 [0.69, 1.02] | 0.085 |
| Ovulation disorder | 1.09 [0.89, 1.34] | 0.407 |
| Endometriosis | 0.56 [0.35, 0.88] | 0.013 |
| Others | 0.74 [0.56, 0.98] | 0.038 |
| Number of IVF attempts – n (%) | 2600 |
| 1 | Reference |
| 2 | 0.82 [0.69, 0.98] | 0.028 |
| 3 | 0.68 [0.49, 0.95] | 0.023 |
| 4 | 0.46 [0.22, 0.97] | 0.043 |
| 5 | 0.36 [0.12, 1.12] | 0.078 |
| ≥6 | 0.63 [0.20, 1.97] | 0.432 |
| Duration of stimulation – days | 2600 | | 0.94 [0.90, 0.98] | 0.005 |
| Total dose of rFSH – IU | 2600 | +300 | 0.93 [0.91, 0.95] | <0.001 |
| Type of trigger – n (%) | 2600 |
| Agonist trigger | Reference |
| hCG trigger | 1.20 [0.97, 1.47] | 0.092 |
| Estradiol level on day of trigger – pg/mL | 2436 | +1500 | 1.00 [0.98, 1.01] | 0.855 |
| Progesterone level on day of trigger – ng/mL | 2430 | +1 | 0.94 [0.87, 1.01] | 0.096 |
| <1.5 | Reference |
| ≥1.5 | 0.78 [0.67, 0.91] | 0.001 |
| Number of oocyte retrieved – n | 2600 | +1 | 1.03 [1.02, 1.04] | <0.001 |
| 1 – 3 | Reference |
| 4 – 9 | 2.20 [0.91, 5.35] | 0.081 |
| 10 – 15 | 3.11 [1.29, 7.50] | 0.012 |
| >15 | 3.37 [1.39, 8.14] | 0.007 |
| Number of embryos – n | 2600 | +1 | 1.07 [1.05, 1.09] | <0.001 |
| Number of good embryos – n | 2600 | +1 | 1.08 [1.06, 1.10] | <0.001 |
| Fresh or frozen transfer during first ET – (n, %) | 2600 |
| FET | Reference |
| Fresh ET | 1.39 [1.21, 1.59] | <0.001 |
| Number of subsequent FET after first transfer – n (%) | 2600 |
| 0 | Reference |
| 1 - 2 | 1.30 [1.13, 1.49] | <0.001 |
| 3 - 4 | 1.61 [1.34, 1.94] | <0.001 |
| ≥5 | 1.80 [1.30, 2.48] | <0.001 |